The man who was meant to unify Japan

According to the Western calendar, January 25 is the anniversary of the Battle of Mikatagahara, fought in 1573. (The actual date of the conflict was Genki 3/12/22, but I'll explain the complexities and problems of dating in the life and career of Tokugawa Ieyasu in another post.) Today I therefore wanted to offer a brief essay on the amazing story of Takeda Shingen's encounters with Ieyasu. Shingen probably should have been the man to unify Japan and perhaps establish the next warrior shogunate after his victory at the Battle of Mikatagahara.

In 1570, Ieyasu bestowed his familial home of Okazaki Castle on his son Takechiyo (Nobuyasu) and shifted his own seat of operations to Hamamatsu (formerly known as Hikuma) Castle in Tôtômi, about 40 miles to the east (in present-day Hamamatsu City, Shizuoka Prefecture). This was a significant shift, since his family had been based in Mikawa Province since the time of his grandfather. Furthermore, he now had a new neighbor to worry about: Takeda Shingen, the ruler of Shinano and Kai Provinces, as well as portions of Mikawa. Shingen was not only one of the most feared and experienced warlords in Japan, he also had been a major ally of the now-defeated Imagawa. He and Ieyasu had initially agreed to a truce of sorts after the death of Imagawa Yoshimoto, but the armistice soon collapsed.

Although Shingen was engaged in an ongoing war with the Hôjô clan to the east, he still had time to harass Ieyasu’s positions in Tôtômi. Ieyasu therefore extended his hand to one of Shingen’s main rivals, the warlord Uesugi Kenshin (1530–78), who ruled Echigo Province to the north. In a letter dated 1570/10/8, Ieyasu expresses his pleasure at the establishment of an alliance with Kenshin and pledges to break off relations with Shingen. He also states his intention to facilitate friendly relations between Nobunaga and Kenshin, thereby isolating Shingen and perhaps forestalling a major conflict with this most dangerous of warlords.(1)

Far from isolating Shingen, the move seems to have goaded him. In addition, Nobunaga had his hands full dealing with the substantial coalition of forces lining up against him in the region around the capital, including the remaining armies of the Azai and Asakura, the True Pure Land headquarters in Osaka, and the warrior monks of Mt. Hiei outside of Kyoto. Ieyasu’s decision to openly make an enemy of Shingen while Nobunaga was engaged elsewhere proved to be quite risky.

Shingen moved against Ieyasu within half a year. After various maneuverings and skirmishes, Shingen’s mounted forces captured Asuke Castle in eastern Mikawa on 1571/4/15. They then turned toward Yoshida Castle, further in the interior of Mikawa. Ieyasu reportedly hastily assembled two thousand men, traveled by horse from Hamamatsu to Yoshida, and entered the castle, putting his own life at stake to protect his territory.(2) This rather dramatic gesture may also have been intended to communicate to Shingen that his invasion would rouse the ire of Ieyasu’s allies Kenshin and Nobunaga unless it was abandoned. Shingen attacked on 4/29 and overwhelmed the outer defenses, but didn’t lay siege to the central keep. Probably for his own reasons—to pursue other campaigns in his rapidly growing territory or perhaps feeling satisfied that he had demonstrated his power—Shingen withdrew. The ease with which Shingen had penetrated Ieyasu’s lands and threatened him and his men probably should have cautioned the young Tokugawa lord to rethink his alliances and hostile position toward the Takeda, but no such reflection is apparent in the documentary record or in Ieyasu’s subsequent actions.

Meanwhile, Shingen received a communication from Shogun Yoshiaki requesting that the Takeda lord attack Nobunaga, which fit in well with his own plans to become the ruler of all of central Japan. He used family ties to negotiate a pact with the True Pure Land headquarters in Ishiyama (Osaka). He also received promises of aid from the warrior monks of Mt. Hiei and Nobunaga’s enemies the Azai and Asakura to the north, which effectively surrounded the Oda lord with hostile forces. This left Uesugi Kenshin and Ieyasu to be dealt with. Kenshin was neutralized by True Pure Land forces who were convinced to rise up against him in his home province by the True Pure Land headquarters in Ishiyama. Ieyasu could be neutralized while moving troops to the west. The larger goal was an attack on Nobunaga and perhaps, if Shingen’s ailing health held out, the capture of Kyoto

Shingen next invaded Tôtômi, driving a huge force of 25,000 across the province. One by one he toppled the outer fortifications of the Tokugawa domain. Next, he feinted towards Kakegawa Castle and Takatenjin Castle, which would have largely isolated Ieyasu at Hamamatsu. Ieyasu fell for the bait and launched his army to the field of Hitokotozaka, where Shingen’s men easily defeated his forces. Ieyasu, however, cleverly assigned his fierce and experienced vassal Honda Tadakatsu to the position of rear guard, to slow down the pursuing enemy and allow Ieyasu to reach safety in Hamamatsu Castle.

Shingen proceeded cautiously in his pursuit of Ieyasu, moving first to topple Futamata Castle to the northeast of Hamamatsu, which would protect his flank when he turned to attack Hamamatsu. However, the siege of Futamata took longer than he had anticipated, and he was unable to topple it until the twelfth month. Ieyasu, who had meanwhile received a few reinforcements from Nobunaga, might have successfully pulled his men into the castle, forcing Shingen into a difficult siege. Instead Ieyasu chose to field his army of approximately 11,000 (which included the 3,000 Oda men) to meet the invaders at Mikatagahara north of Hamamatsu. He reportedly spread his forces in a formation known as “crane’s wing” (kakuyoku) with the goal of enclosing the much larger Takeda force (though the use of these Chinese techniques may be later glosses). This was, however, a strategy that Shingen knew well, having used it on several occasions, and he reportedly arranged his men in the “fish scale” (gyôrin) formation, which easily penetrated the opposing lines. On 12/22, the Takeda forces routed the combined Oda and Tokugawa armies, and Ieyasu fled to Hamamatsu Castle while the remaining Oda soldiers escaped north to Owari. That evening Ieyasu’s vassals Ôkubo Tadayo and Amano Yasukage gathered together all the arquebuses (teppô) to be found and launched a night assault on the encamped Takeda forces, but to little effect.(3) Shingen had won the Battle of Mikatagahara comprehensively. Ieyasu found himself at the old warlord's mercy.

Around this time, Shingen received word that Azai and Asakura, key components in his plan to surround Oda Nobunaga, were withdrawing their forces from northern Tôtômi. Shingen demanded their observance of his carefully laid plans, and then seems to have decided to move his forces farther to the west to put more pressure on Nobunaga himself. Though it seems likely that he had originally intended to destroy Ieyasu, he had at least neutralized any possible Tokugawa threat and furthermore proven again his military superiority to his young enemy. Shingen therefore moved his troops into Mikawa and after various engagements lay siege in early 1573 to one of Ieyasu’s fortifications, Noda Castle.(4) Ieyasu was unwilling or unable to respond in person, but sent notification of these events to Uesugi Kenshin, asking him to send soldiers into Shinano Province to draw Shingen away from Mikawa. He included a long sword as a gift for Kenshin, a trend that I discuss in the book in some detail.(5) The siege went badly until Shingen cut off the water supply, which forced the castle to open its gates in the second month, allowing Shingen to take over the keep. Shingen seemed unstoppable.

However, over the next month or so Shingen’s movements are unclear. Documents record that he sent his troops to attack other fortresses and to engage with some Oda forces in Mino, but he himself seems to have grown sicker at the end of the third month, forcing him to begin retreating to his home province of Kai. On 1573/4/12, on the road home through Shinano Province, Takeda Shingen died at the age of fifty-two. His son Katsuyori took over the leadership of the Takeda clan, but was never able to rise to the heights of his father.(6) The man who had seemed destined to unify Japan died not of a battlefield wound, it seems, but of disease.

1. Nakamura, Tokugawa Ieyasu monjo no kenkyû, 1:165.2. Entry for Genki 2/4/29 in Tokyo Daigaku Shiryô Hensanjo, ed., Dai Nihon shiryô, ser. 10, vol. 6, pp. 190-197.3. Many historians have narrated this battle and its context. One useful summary can be found in Morita Kôji, “Mikatagahara no tatakai,” in Tokugawa Ieyasu jiten, ed. Fujino Tamotsu et al. (Tokyo: Shinjinbutsu Ôraisha, 1990), 200-207. It is also worth noting that this battle was the object of more scrutiny in contemporaneous documents than any other event in Ieyasu’s life to this point. See, for example, the many excerpts in Tokyo Daigaku Shiryô Hensanjo, ed., Dai Nihon shiryô, beginning with the entry on Genki 3/12/22 in ser. 10, vol. 11, p. 8.4. Entry for Tenshô 1/2/17 in Tokyo Daigaku Shiryô Hensanjo, ed., Dai Nihon shiryô, ser. 10, vol. 14, p. 49. 5. Nakamura, Tokugawa Ieyasu monjo no kenkyû, 1:196-7.6. Accounts of the final months and death of Shingen in the Japanese primary and secondary sources vary widely. I am relying on my own reading of sources collected in Dai Nihon shiryô, ser. 10, vol. 15, 98-100.